This invention relates to a keypad apparatus and more particularly to a keypad apparatus which employs snap-in modular planar component assemblies.
The prior art is replete with numerous keypad or keyboard devices which are used for example in conjunction with telephone subsets to implement dialing. The typical telephone subset, for example, contains an array of 12 buttons which formulate a keypad enabling a user to dial in various numbers and to utilize two special keys for implementing various other requests. Such keypads have been widely employed in the intrusion detection field whereby the keypads are utilized with control panels in order to allow a user of an intrusion system to implement various system functions via the keypad. As one can ascertain, keypads are widely used in numerous other applications such as access control systems, automatic bank teller systems, calculators, and so on.
Thus, the use of keypads is relatively extensive and they are widely employed in a host of different applications. One will readily understand that the prior art is replete with numerous keypad configurations and structures which implement keypads which utilize various switching techniques and so on. The prior art is extensive and there exists various different types of keypads for use in all of the above applications.
Based on such use, it is, of course, apparent that there is a need for a keypad which is extremely economical to manufacture and extremely simple to construct while providing high reliability. A major problem that exists in many keypads is that in order to achieve reliable operation, one must depress a given button or key associated with the keypad relatively at the center to assure reliable operation. In this manner, when depressing the button at a central location, one can be sure that the proper signal is forwarded to the decoding circuitry. If a key is struck at a side or off center, oftentimes contact is not made and therefore the user does not really register the particular digit. This can create many problems in that depression of a key or button off center will not close the switch. As one can understand, it is important that a user when attempting to access a button associated with the keypad can operate the same reliably and even if the operating force is applied off center.
It is, therefore, an object of the present invention to provide a reliable operating keypad apparatus which is economical and simple to manufacture.
It is yet a further object of the present invention to provide a modular keypad employing a unique contact design which allows consistent switching when a key is depressed at its edge rather than at dead center.
It is a further object of the present invention to provide a modular keypad apparatus which employs snap-in components while enabling one to achieve reliability in an economical configuration.
The keypad to be described utilizes modular snap-in components which are easily inserted into posts associated with a frame member.